Watch-case spring



(No Model.)

A. GRANDJEAN.

WATCH CASE SPRING.

No. 311,894. Patented Feb. 10,1885.

N. PETERS, Phom-Liibognphur. Walllmglon. n. c

a break in the continuity of the spring.

UNITED STATES PATENT OFFICE.

ARTHUR GRANDII'QAN, OF CIXCIXNATT, OHIO.

WATCH-CASEVSPRING.

SPECIFICATION forming part of Letters Patent No. $11,894:,dated February10,1885.

Application flied August 25, 168 1. (No model.)

To aZZ whom it may concern.-

Be it known that I, ARTHUR Gatxnamx, a citizen of the United States, anda resident of Cincinnati, in the county of Hamilton and State of Ohio,have invented a new and useful \Vateh-Case Spring, of which thefollowing is a specification.

My invention relates to the springs of a Watch-case, and which are knownas catch and lift springs; and it consists of the construction in commonof the eatclrspring which locks the cover, and of the lift-spring whichthrows the cover back when it is relieved by the catch-spring.

The object of my invention is to produce a spring embodying both a catchand a lift spring for a watch-case in common, and which shallbe'superior to the springs previously devised in simplicity ofconstruction and facility of placing in and removing from the case, andin cheapness of construction, and, above all, which shall not be liableto breakage.

Figure 1 is a side view showing the e011- tinuous side and the catch 2,and thelii't-hook 3 diametrically opposite. Fig. 2 is a plan of thespring shown in position in the springchamber, which is indicated by thedotted lines 9 and 10. Fig. 3 is a view of the side opposite the oneshown in Fig. 1, and shows Fig. 4 is a front view.

The sameletters or numbers indicate the same parts in all of theiigures.

The spring consists of a continuous piece of spring metal bent into aslightly-elliptical form, as shown in Fig. 2, and has a suture joint atthe middle of one side, as shown in Figs. 2 and 3. The catch 2 forlocking the cover and the hook 3 for lifting the same are placeddiametrically opposite each other, the catch being at the front and thehook at the back of the spring.

From an inspection of the figures it will be seen that the greatestdepths and cross-sections of the spring-body '1. are at the front wherethe catch is located, at the middle of the con tinuous side, and at themiddle of the opposite side where the joint is located. The catch 2 isof the usual construction, and is an up ward projection in common withthe body of the spring at its front. A hole, 4, is made through thespring-front directly beneath the catch 2 for the stem or the key-pipe,as usual, when the spring is used in a stem-winder. The front part ofthe spring tapers oft gradually and symmetrically from each side of thecatch to near the middle of the sides, where its branches similarlyincrease in depth until they merge into the middle portions, 5 and 6,which have the same depth as the section at the catch, the topedge ofthe spring, however,

being in the same plane throughout its entire length. Each side of thespring beyond the middles 5 and 6 of the sides tapers off gradually andsymmetrically until a uniform section is attained at the lift-hook. Thelift-hook 3 projects upward from and is in common with the centralportion of the back of the spring. The hook 3 projects upward and curvesoutward, and slightly tapers toward the extremity. \V here the springmetal is very rigid the sections of the tapered portions of the springon each side of the hook 3 may be further gradually reduced to lesssections than that at the hook. The joint at the middle of the side 6 ofthe spring consists of a gap, '7, cut into the end of one branch, andot' a tongue, 8, formed on the end of the other branch, of a size andshape adapted to slip into the gag 'T. The tongue 8 is formed by cuttingout a gap at each corner 01. the end and leavinga central part intact,so that there is a shoulder on each side of the tongue. The tongue isbent inward, and when the spring is in place in the ease-center, asshown in Fig. 2, and the catch and lift-hook are properly adjusted, thespring is under pressure toward the center along the diameter throughthe catch and the lift-hook, and eonsequentl y the tongue 8 ismaintained engaged within the gap 7, so that the spring, when in placeand adjustment, acts as an unbroken hoop-spring. The spring ismaintained in position within the spring-chamber by the engagement ofthe catch at the front and the lift-hook at the back. There need be nopressure laterally against the walls of the spring-chamber either whenidle or when in action, and since there is no possibility of a testedspring so constructed ever breaking by use this spring could be used ina watch-case not having any protecting ring or wall between the movementand the sprin hen the spring is idle there is no pressure parallel tothe depth of the spring against the interior of the center, or the topor the bottom of the spring-charm ber. The spring, then, is to beconsidered as a slightly-elliptical hoop suspended within thespring-chamber from the catch and the lifthook, and as free to movethroughout its circumference by fieXure whenever compressed at eitherthe catch or the lift-hook. For example, when the catch is pressedinward, the hook becomes the stationary point, and as the long diameterof the ellipse is diminished the elliptical circumference is subjectedto flexure throughout its extent and, approaches a circular form. Thekey passes through the hole 4: beneath the catch and the shoulder on thestem, or the end of the key-pipe abuts against the exterior of thespring, and thus by pressing the crown inward the front of the spring ispressed inward also, and carries the catch with it. The action of thespring, then, when the catch is pushed in ward, is like that of a hoopsecured at one point and pressed inward at the point diametricallyopposite, and the flexure is all in the same plane, so that there is norubbing or friction on the walls of the springchamber or upon the ringsurrounding the movement where such ring is used. The llexure of thespring will be greatest of course at the re dueed sections. The actionof the spring when the cover acts upon the lift-hook is somewhatdifferent. \Vhen the cover is th rown back, the extremity of thelift-hook is in contact with the edge of the cover contiguous to thehinge, and the upper even edge of the spring is parallel with theadjacent top wall of the springchamber. The action upon the spring whenthe cover is first moved forward in closing it is the same as when thecatch is pressed inward; but when the cover is further closed the backportion of the spring, in addition to being bent inward, is bentdownward until the lower edges of the deep sections intermediate betweenthe catch and the lift-hook comeinto contact with and press down uponthe bottom of the spring-chamber, when further downward 'llexnre takesplace from these points back to the lift-hook. The slender portions ofthe spring on each side of the lift-hook permit of gentle and uniformflexure, and are free to bend inward and downward without coming incontact with the walls of the spring-chant ber. XVhen the cover isreleased by the catch 2,the spring,being under pressure, reacts upon thecover and throws it back. As has been seen, the tapered or diminishedportions of the spring are gradually reduced in cross-section, and areof considerable length and symmetrically disposed, while there isfreedom of action and provision for llCXlOll throughout the whole sprinConsequently this spring, when properly made, tested, and adjusted,cannot possibly break.

The spring is to be made of llat metal and stamped or cut out bymachinery into the approximate form which the spring shown in thefigures would have if unrolled or flattened out. The catch and the lifthook and the parts of the joint '7 S are then to be properly shaped,and, if necessary, the surface of the spring may be smoothed off. Thespring is then to be bent into the elliptical or circular form shown,the joint made to work properly, and then the spring is to be tempered.

Many of the disadvantages of various catch and lift springs previouslydevised are given in a patent to \V. H. Fitz Gerald and G. C. Smith,April 22, 1884, No. 297,123. Nosuch defects exist in my improvedhoop-spring. My springis easily placed and adjusted within thespringchamber of a case.

In placing my spring in a center opening centrally the front part isfirst inserted into the spring-chamber and'the catch slipped into itsnotch. The forefinger is then applied to the middle of the continuousside, and this side is pressed inward until the lift-hook catches in itsnotch. The end beyond the lift-hook will then spring into place, and bypressing the thumb-nail against the end it will engage and lock with thetongue 011 the other end, and will then be in adjustment.

To remove the spring, the end having the tongue is pressed back orradially outward from the center of the case, when the end having thegap is released and springs inward far enough to be grasped between thethumb and forefinger, and hence easily removed.

1. A watch-case spring consisting of a hoop having its ends joinedtogether at a point be tween the catch and the lift-hook, aml having incommon therewith a catch for locking the case-cover and a lift-hook forengaging with the hinge of the cover.

2. A watch-case spring consisting of ahoop made continuous by means ofajoint located in the middle portion of one side and between the catchand the lilthook, and having a hole adjacent the catch for the stem orkey-pipe, and having the body of the spring on each side of the catchreduced in cross-section, while the middle portions of each side of thespring have a depth correspondin to that at the catch, and the sidesbeyond the middle tapered off to a uniform section at and near thelift-hook.

S. A watch-case spring consisting of a hoop made continuous by means ofajoint located in the middle portion of one side and between the catchand the lift-hook, and having a hole adjacent the catch for the stem orkey-pipe, and having the body of the spring on each side of the catchreduced in cross-section, while the middle portions of each side of thespring have a depth corresponding to that ICO at the catch, and thesidesbeyond the middle may be made continuous and its action be tapered offto a uniform section at and near made the same as if both sides of thehoop the lift-hook, and the joint consisting of a gap were solid.

in the end of one extremity of the spring, and ARTHUR GRANDJEAN. 5 of atongue at the other extremity, to inter- XVitnesses:

look within the said gap and unite the said EDWARD P. ROBBINS,

extremities of the hoop whereby the hoop ROBERT ZAHNER.

